I'm unable to generate a new form for a task with either the 1.0 JBDS bits or Eclipse Europa + jbpm-jpdl-designer-3.0.13 Stable 9.2 MB 2007-01-25
To recreate the problem - using the attached jBPM process project - it's based on the 'holiday request' jBPM demo - at the start task node, attempt to generate a form.
The screen displayed in the screenshot attachment is brought up - pressing OK has no effect. The form xhtml file is not created - and no error/sttaus message is displayed.